In the area of writing on media and reading therefrom by means of magnetic ink characters, one of the important aspects of the several operations is to provide method and apparatus for maintaining the media in a position in relation to the write and/or read heads so as to obtain a clear and precise working operation, while at the same time permitting a free flow path for the media past the heads. The media may be in any one of several forms including tapes or webs, documents and cards or the like, such media having space provided thereon for receiving information in one manner or another to be retained for later reading thereof. In the case of tape or web-like media, it is presently the state of the art to provide the information or characters in magnetic ink on the tape or web by magnetic charges deposited thereon for reading the desired information at a later time. It has also been a practice to provide on documents, such as checks or the like, characters in magnetic code for identification purposes during the processing operation, the most common application being that of sorting bank checks in high speed operations. In the manner of processing these checks, a number of them are deposited in a bin or hopper and then are selected in individual manner to be transported along a path where the checks may be further processed to add additional information thereto or to read certain information from the checks to be used in the further processing thereof.
Since the several operations are performed at the highest velocities practicable, it is essential that the documents are transported in a free flowing manner while the addition of or the reading of certain information is accurate and clear in processing the data. Therefore, the positioning of the document in relation to the read and/or write heads must be necessarily precise so as not to miss any information during the processing operation.
Representative of prior art, in the manner of positioning media in data processing apparatus, is British Pat. No. 1,110,141 which discloses a tape transport mechanism with a record-playback head and an erase head, and wherein a pair of pressure pads cooperate with the heads, the pads being mounted on a plate slidably mounted on the tape deck, and the plate being guided by a pair of lugs. The tape is biased against the heads by a spring which is connected between the plate and the deck. Frederick U.S. Pat. No. 3,109,924 shows record handling and reading apparatus having magnetizing and reading heads, and a spring-loaded flexible non-conductive band bearing against the surface of a drum carrying the reading head to bring the back surface of the document into close proximity with the head. Nettleton et al. U.S. Pat. No. 3,393,277 discloses a tape transport with independently operable drive and brake means at record and reproduce stations with a felt pressure pad, loaded by a U-shaped spring, to urge the tape against the respective heads. Hammond U.S. Pat. No. 3,402,868 shows a tape drive arrangement for a pair of transducer heads with springs urging pressure rollers against the peripheral surface of the drive capstan. Orzechowski U.S. Pat. No. 3,629,556 discloses card reading mechanism with a plastic pressure pad supported on a spring arm to urge the pad toward a transducer having a curved face. Bach U.S. Pat. No. 3,648,023 discloses a reading and/or writing device for record carriers in card form wherein a spring urges against a fence having a magnetic head thereon. Von Glahn et al. U.S. Pat. No. 3,801,804 discloses a drum driven document back-up roller having a pair of read heads and spring loaded back-up holding means to bias a document against the surface of the heads. And, Shore U.S. Pat. No. 3,822,835 shows a tape cartridge having a pair of foam backing pads adjacent the transducer openings and held in place by two pairs of pins for each pad.